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/*
* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
/******************************************************************
iLBC Speech Coder ANSI-C Source Code
WebRtcIlbcfix_GetSyncSeq.c
******************************************************************/
#include "modules/audio_coding/codecs/ilbc/get_sync_seq.h"
#include "modules/audio_coding/codecs/ilbc/constants.h"
#include "modules/audio_coding/codecs/ilbc/defines.h"
#include "modules/audio_coding/codecs/ilbc/nearest_neighbor.h"
#include "modules/audio_coding/codecs/ilbc/refiner.h"
/*----------------------------------------------------------------*
* get the pitch-synchronous sample sequence
*---------------------------------------------------------------*/
void WebRtcIlbcfix_GetSyncSeq(
int16_t *idata, /* (i) original data */
size_t idatal, /* (i) dimension of data */
size_t centerStartPos, /* (i) where current block starts */
size_t *period, /* (i) rough-pitch-period array (Q-2) */
const size_t *plocs, /* (i) where periods of period array are taken (Q-2) */
size_t periodl, /* (i) dimension period array */
size_t hl, /* (i) 2*hl+1 is the number of sequences */
int16_t *surround /* (i/o) The contribution from this sequence
summed with earlier contributions */
){
size_t i, centerEndPos, q;
/* Stack based */
size_t lagBlock[2 * ENH_HL + 1];
size_t blockStartPos[2 * ENH_HL + 1]; /* The position to search around (Q2) */
size_t plocs2[ENH_PLOCSL];
centerEndPos = centerStartPos + ENH_BLOCKL - 1;
/* present (find predicted lag from this position) */
WebRtcIlbcfix_NearestNeighbor(lagBlock + hl,
plocs,
2 * (centerStartPos + centerEndPos),
periodl);
blockStartPos[hl] = 4 * centerStartPos;
/* past (find predicted position and perform a refined
search to find the best sequence) */
for (q = hl; q > 0; q--) {
size_t qq = q - 1;
size_t period_q = period[lagBlock[q]];
/* Stop if this sequence would be outside the buffer; that means all
further-past sequences would also be outside the buffer. */
if (blockStartPos[q] < period_q + (4 * ENH_OVERHANG))
break;
blockStartPos[qq] = blockStartPos[q] - period_q;
size_t value = blockStartPos[qq] + 4 * ENH_BLOCKL_HALF;
value = (value > period_q) ? (value - period_q) : 0;
WebRtcIlbcfix_NearestNeighbor(lagBlock + qq, plocs, value, periodl);
/* Find the best possible sequence in the 4 times upsampled
domain around blockStartPos+q */
WebRtcIlbcfix_Refiner(blockStartPos + qq, idata, idatal, centerStartPos,
blockStartPos[qq], surround,
WebRtcIlbcfix_kEnhWt[qq]);
}
/* future (find predicted position and perform a refined
search to find the best sequence) */
for (i = 0; i < periodl; i++) {
plocs2[i] = plocs[i] - period[i];
}
for (q = hl + 1; q <= (2 * hl); q++) {
WebRtcIlbcfix_NearestNeighbor(
lagBlock + q,
plocs2,
blockStartPos[q - 1] + 4 * ENH_BLOCKL_HALF,
periodl);
blockStartPos[q]=blockStartPos[q-1]+period[lagBlock[q]];
if (blockStartPos[q] + 4 * (ENH_BLOCKL + ENH_OVERHANG) < 4 * idatal) {
/* Find the best possible sequence in the 4 times upsampled
domain around blockStartPos+q */
WebRtcIlbcfix_Refiner(blockStartPos + q, idata, idatal, centerStartPos,
blockStartPos[q], surround,
WebRtcIlbcfix_kEnhWt[2 * hl - q]);
} else {
/* Don't add anything since this sequence would
be outside the buffer */
}
}
}
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